In many industrial installations, a large supply of water is often needed for cooling, flushing, or other applications. Such a large supply of water is usually taken from a body of water, such as a river, stream, pond or other water source, which contains particulate material, such as leaves, twigs, stones and the like, that would be harmful to industrial equipment and which particulate material must be removed. In order to remove such particulates, an initial bar screen may be used to filter out the largest articles, while other particulates are fed to a straining apparatus which may be a rotary strainer containing a rotary basket screen or other device to remove particulates.
The assignee of the present invention has, for example, provided strainers which are adapted for service on a suction side of pumps to strain liquid of foreign matter, and one such device is of a motorized self-cleaning type that contains a strainer basket in a housing, which basket is motor driven. A support with spokes suspends the strainer basket in the housing, while a brush, shear knife and/or water jet device is used to clean the strainer basket sidewall. A revolving brush on the outside of the strainer basket keeps the strainer basket openings free from clogging, while a shear knife on the outside of the strainer basket shears any protruding matter from the basket as it revolves, and high pressure cleaning jets pressure clean the strainer basket as it revolves, forcing debris from the strainer basket and its openings. While this type of device is eminently suited for most applications, the support and spokes are positioned in the flow of water containing particulates and collection of debris thereon or wearing of the same by contact with the particulate-containing water would best be avoided.
It is an object of the present invention to provide a self-cleaning strainer where the apparatus used to rotate the strainer basket is positioned out of the flow of liquid containing particulates that is fed to the strainer basket.
It is another object of the present invention to provide cleaning devices for the wall of the strainer that better act to clean the openings and inner surface of the wall of the strainer basket.